1. Field of the Invention
This invention relates generally to power management and more particularly to a method and apparatus to reduce the power consumption of portable devices to increase battery life by dynamically modifying a clock speed of a processor.
2. Description of the Related Art
Portable electronic devices rely on batteries to provide the necessary power for the operation of the device. Consumers using the portable devices want to be able to use the devices for longer time periods in between having to recharge the batteries. As such, there is a continual effort to increase battery performance and to perform the operations in more energy efficient ways, even as the applications performed by the devices become more sophisticated, and in some cases, require more power.
The central processing unit (CPU) is generally the largest consumer of power for the portable computing devices. However, the power consumption of the CPU is generally not capable of being modified for the various applications being executed. That is, there is a one size fits all approach for the power consumption of the microprocessors for the devices even though some applications require only a fraction of the CPU power. For example, when watching a movie on a laptop computer having a digital video disc (DVD) player, a clock speed of only up to about 20% of the operating clock speed of the CPU may be necessary. While there has been some attempts to reduce the power consumption of microprocessors, none allow for the power consumption to be modified based upon a predicted application demand. Furthermore, when the operating system is placed into an idle mode, the CPU clock frequency does not change. Therefore, the power consumption of the CPU remains unnecessarily high.
As a result, there is a need to solve the problems of the prior art to provide a method and apparatus for reducing the power consumption of microprocessors, such as CPUs, where the power consumed by the CPU is based upon the application being executed.